LC
Grey Gull Larus modestus



Taxonomy

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: #http://www.museum.lsu.edu/~Remsen/SACCBaseline.htm#.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2018 Least Concern
2016 Least Concern
2012 Least Concern
2009 Least Concern
2008 Least Concern
2004 Least Concern
2000 Lower Risk/Least Concern
1994 Lower Risk/Least Concern
1988 Lower Risk/Least Concern
Species attributes

Migratory status full migrant Forest dependency Does not normally occur in forest
Land mass type Average mass 344 g
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 106,000 medium
Extent of Occurrence non-breeding (km2) 3,150,000 medium
Number of locations -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals poor estimated 2006
Population trend Decreasing suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations - - -
Largest subpopulations - - -
Generation length (yrs) 11.5 - - -

Population justification: Delany and Scott (2006) estimate the population at 25,000 individuals.

Trend justification: The population is suspected to be in decline owing to ongoing threats.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Chile N Extant Yes
Colombia N Extant
Costa Rica N Extant Yes
Ecuador N Extant Yes
Falkland Islands (Malvinas) N Extant
Panama V Extant
Peru N Extant Yes
South Georgia & the South Sandwich Islands U Extant

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Peru Isla Pachacámac
Peru Laguna de Ite
Peru Reserva Nacional de Paracas
Peru Río Tambo y Lagunas de Mejía
Chile Desembocadura del Río Lluta
Chile Costa sur de Arica
Chile Pampa del Colupo
Chile Desembocadura del Río Maipo
Chile Playa Sur de Arica
Chile Playa las Machas
Chile Playa sector Chacalluta
Chile Desembocadura Río Mataquito
Chile Santuario de la Naturaleza Humedal Laguna Reloca
Chile Bahía de Mejillones
Chile Costa de Quintero y Mar Adyacente (Pelagico)
Chile Parque Nacional Pan de Azúcar
Chile Reserva Nacional Pingüino de Humboldt - Isla Choros, Damas y Punta de Choros

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Intertidal Sandy Shoreline and/or Beaches, Sand Bars, Spits, Etc major non-breeding
Marine Neritic Macroalgal/Kelp major non-breeding
Marine Neritic Macroalgal/Kelp major breeding
Marine Neritic Pelagic suitable non-breeding
Marine Neritic Pelagic suitable breeding
Marine Neritic Seagrass (Submerged) major non-breeding
Marine Neritic Seagrass (Submerged) major breeding
Marine Neritic Subtidal Loose Rock/pebble/gravel major non-breeding
Marine Neritic Subtidal Loose Rock/pebble/gravel major breeding
Marine Neritic Subtidal Rock and Rocky Reefs major non-breeding
Marine Neritic Subtidal Rock and Rocky Reefs major breeding
Marine Neritic Subtidal Sandy major non-breeding
Marine Neritic Subtidal Sandy major breeding
Marine Neritic Subtidal Sandy-Mud major non-breeding
Marine Neritic Subtidal Sandy-Mud major breeding
Altitude   Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Causing/Could cause fluctuations Low Impact: 5
Stresses
Reduced reproductive success
Climate change & severe weather Temperature extremes Timing Scope Severity Impact
Ongoing Majority (50-90%) Causing/Could cause fluctuations Medium Impact: 6
Stresses
Indirect ecosystem effects, Reduced reproductive success
Energy production & mining Mining & quarrying Timing Scope Severity Impact
Ongoing Minority (<50%) Causing/Could cause fluctuations Low Impact: 5
Stresses
Species disturbance, Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Canis familiaris Timing Scope Severity Impact
Ongoing Minority (<50%) Causing/Could cause fluctuations Low Impact: 5
Stresses
Species disturbance, Reduced reproductive success

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Food - human - - Non-trivial Recent
Pets/display animals, horticulture - - International Non-trivial Recent

Recommended citation
BirdLife International (2020) Species factsheet: Larus modestus. Downloaded from http://www.birdlife.org on 10/07/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 10/07/2020.